/**
* OK, so we have a binary str of len n. Each time we're allowed to give a str and
* whether the str is a substr of the original binary str is returned. The task is
* to determine the entire str under a certain num of interactions.
*
* Well it looks to me that the num of steps shall be O(n). Well, i think i've got
* a solution by extending the current str on either side. 2n steps is now the
* maximum. Using randomized algo, we can prove that the expected num of
* interactions <= 1.5n, which is still too much, and whether the interactor is
* adaptive remains unknown.
*
* We want to further lower the num of interactions. Can we directly determine the
* first char? Well i guess the goal is to find the suffix (or equivalently the
* prefix). In the algo above, we extend our str on the right side until it can
* no longer be extended; after this, we can just extend it on the left side,
* without fearing that a "true" response corresponds to a substr which is not a
* suffix (shifted pos). In other words, we wish to find a substr such that:
* make_test((substr)0), make_test((substr)1) are all false.
*
* Number of steps: 1.5 (expected)
* Implementation 1
*/
#include <bits/stdc++.h>
#include "dna.h"
std::string analyse(int n, int T) {
std::string current = "";
for (;;) {
std::vector<char> test({'0', '1'});
std::random_shuffle(test.begin(), test.end());
bool found = false;
for (char c : test) {
if (make_test(current + c)) {
current.push_back(c);
found = true;
break;
}
}
if (!found) // can't append any char (at the back)
break;
}
assert(int(current.size()) <= n);
while (int(current.size()) < n) {
if (make_test("0" + current))
current.insert(0, 1, '0');
else
current.insert(0, 1, '1');
}
return current;
}
Compilation message
grader.cpp: In function 'bool make_test(std::string)':
grader.cpp:14:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
14 | for (int i = 0; i < p.size(); i++) {
| ~~^~~~~~~~~~
grader.cpp:23:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
23 | for (int i = 1; i <= ss.size(); i++) {
| ~~^~~~~~~~~~~~
grader.cpp:28:13: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
28 | if (pr[i] == p.size()) {
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Correct |
0 ms |
212 KB |
Output is correct |
| 3 |
Correct |
0 ms |
212 KB |
Output is correct |
| 4 |
Correct |
0 ms |
212 KB |
Output is correct |
| 5 |
Correct |
0 ms |
212 KB |
Output is correct |
| 6 |
Correct |
1 ms |
212 KB |
Output is correct |
| 7 |
Correct |
0 ms |
212 KB |
Output is correct |
| 8 |
Correct |
0 ms |
212 KB |
Output is correct |
| 9 |
Correct |
0 ms |
212 KB |
Output is correct |
| 10 |
Correct |
0 ms |
212 KB |
Output is correct |
| 11 |
Correct |
0 ms |
212 KB |
Output is correct |
| 12 |
Correct |
0 ms |
212 KB |
Output is correct |
| 13 |
Correct |
0 ms |
212 KB |
Output is correct |
| 14 |
Correct |
0 ms |
212 KB |
Output is correct |
| 15 |
Correct |
0 ms |
212 KB |
Output is correct |
| 16 |
Correct |
0 ms |
212 KB |
Output is correct |
| 17 |
Correct |
0 ms |
212 KB |
Output is correct |
| 18 |
Correct |
0 ms |
212 KB |
Output is correct |
| 19 |
Correct |
0 ms |
212 KB |
Output is correct |
| 20 |
Correct |
0 ms |
212 KB |
Output is correct |
| 21 |
Correct |
0 ms |
212 KB |
Output is correct |
| 22 |
Correct |
0 ms |
212 KB |
Output is correct |
| 23 |
Correct |
0 ms |
212 KB |
Output is correct |
| 24 |
Correct |
0 ms |
212 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Correct |
0 ms |
212 KB |
Output is correct |
| 3 |
Correct |
0 ms |
212 KB |
Output is correct |
| 4 |
Correct |
1 ms |
212 KB |
Output is correct |
| 5 |
Correct |
0 ms |
212 KB |
Output is correct |
| 6 |
Correct |
0 ms |
212 KB |
Output is correct |
| 7 |
Correct |
0 ms |
212 KB |
Output is correct |
| 8 |
Correct |
0 ms |
212 KB |
Output is correct |
| 9 |
Correct |
0 ms |
212 KB |
Output is correct |
| 10 |
Correct |
0 ms |
212 KB |
Output is correct |
| 11 |
Correct |
0 ms |
212 KB |
Output is correct |
| 12 |
Correct |
0 ms |
212 KB |
Output is correct |
| 13 |
Correct |
0 ms |
212 KB |
Output is correct |
| 14 |
Correct |
0 ms |
212 KB |
Output is correct |
| 15 |
Correct |
0 ms |
212 KB |
Output is correct |
| 16 |
Correct |
0 ms |
212 KB |
Output is correct |
| 17 |
Correct |
1 ms |
212 KB |
Output is correct |
| 18 |
Correct |
0 ms |
212 KB |
Output is correct |
| 19 |
Correct |
1 ms |
212 KB |
Output is correct |
| 20 |
Correct |
1 ms |
212 KB |
Output is correct |
| 21 |
Correct |
1 ms |
212 KB |
Output is correct |
| 22 |
Correct |
1 ms |
212 KB |
Output is correct |
| 23 |
Correct |
1 ms |
212 KB |
Output is correct |
| 24 |
Correct |
1 ms |
212 KB |
Output is correct |
| 25 |
Correct |
1 ms |
212 KB |
Output is correct |
| 26 |
Correct |
0 ms |
212 KB |
Output is correct |
| 27 |
Correct |
1 ms |
212 KB |
Output is correct |
| 28 |
Correct |
1 ms |
212 KB |
Output is correct |
| 29 |
Correct |
0 ms |
212 KB |
Output is correct |
| 30 |
Correct |
1 ms |
212 KB |
Output is correct |
| 31 |
Correct |
0 ms |
212 KB |
Output is correct |
| 32 |
Correct |
1 ms |
212 KB |
Output is correct |
| 33 |
Correct |
1 ms |
212 KB |
Output is correct |
| 34 |
Correct |
0 ms |
212 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Correct |
1 ms |
212 KB |
Output is correct |
| 3 |
Correct |
0 ms |
212 KB |
Output is correct |
| 4 |
Correct |
0 ms |
212 KB |
Output is correct |
| 5 |
Correct |
1 ms |
212 KB |
Output is correct |
| 6 |
Correct |
0 ms |
212 KB |
Output is correct |
| 7 |
Correct |
0 ms |
212 KB |
Output is correct |
| 8 |
Correct |
0 ms |
212 KB |
Output is correct |
| 9 |
Correct |
0 ms |
212 KB |
Output is correct |
| 10 |
Correct |
0 ms |
212 KB |
Output is correct |
| 11 |
Correct |
1 ms |
212 KB |
Output is correct |
| 12 |
Correct |
0 ms |
212 KB |
Output is correct |
| 13 |
Correct |
0 ms |
212 KB |
Output is correct |
| 14 |
Correct |
0 ms |
212 KB |
Output is correct |
| 15 |
Correct |
0 ms |
212 KB |
Output is correct |
| 16 |
Correct |
0 ms |
212 KB |
Output is correct |
| 17 |
Correct |
1 ms |
212 KB |
Output is correct |
| 18 |
Correct |
0 ms |
212 KB |
Output is correct |
| 19 |
Correct |
1 ms |
212 KB |
Output is correct |
| 20 |
Correct |
1 ms |
212 KB |
Output is correct |
| 21 |
Correct |
1 ms |
212 KB |
Output is correct |
| 22 |
Incorrect |
11 ms |
340 KB |
Too many tests |
| 23 |
Incorrect |
12 ms |
340 KB |
Too many tests |
| 24 |
Incorrect |
13 ms |
344 KB |
Too many tests |
| 25 |
Incorrect |
14 ms |
316 KB |
Too many tests |
| 26 |
Incorrect |
11 ms |
312 KB |
Too many tests |
| 27 |
Incorrect |
8 ms |
376 KB |
Too many tests |
| 28 |
Incorrect |
8 ms |
340 KB |
Too many tests |
| 29 |
Incorrect |
8 ms |
340 KB |
Too many tests |
| 30 |
Incorrect |
8 ms |
364 KB |
Too many tests |
| 31 |
Incorrect |
10 ms |
432 KB |
Too many tests |
| 32 |
Incorrect |
9 ms |
340 KB |
Too many tests |
| 33 |
Incorrect |
9 ms |
360 KB |
Too many tests |
| 34 |
Incorrect |
8 ms |
340 KB |
Too many tests |
| 35 |
Incorrect |
9 ms |
340 KB |
Too many tests |
| 36 |
Incorrect |
8 ms |
336 KB |
Too many tests |
| 37 |
Incorrect |
8 ms |
340 KB |
Too many tests |
| 38 |
Incorrect |
9 ms |
328 KB |
Too many tests |
| 39 |
Incorrect |
9 ms |
340 KB |
Too many tests |
